The present invention is directed to a toothbrush, either manual or powered, which includes a handle and a head. Cleaning elements are mounted to the head such as tufts of bristles and/or elastomeric wipers. When toothpaste is applied to the cleaning elements the user inserts the head into the mouth and brushes the teeth in a known manner.
The head of a conventional toothbrush usually has a flat or slightly altered surface to which cleaning elements are attached. Usually the cleaning elements are strands of plastic material(s) formed into tufts, bundles or other groupings. A goal of many toothbrushes is to accommodate the cleaning element profile to that of the teeth being cleaned. Achieving that goal is complicated by the difficulty in matching a toothbrush profile to the complex surface of a typical set of human teeth. The latter generally lie in a “C” shaped curve which presents the need for a brush to address a convex outer curve and a concave inner curve. In addition, the toothbrush should be capable of cleaning irregularities on the tooth surface as well as the interproximal area between teeth.
Various approaches have been taken in the prior art to accommodate the complex shape of the human mouth and the attendant difficulties in cleaning teeth and gums within the mouth. One approach to this problem is provision of a flexible toothbrush head.
Blakeman U.S. Pat. No. 2,706,825 issued Apr. 26, 1955 discloses a replaceable bristle head for a toothbrush. The flexible head undulates in a manner so that rows of bristles move in a direction aligned with the axis of the toothbrush handle.
U.S. Pat. No. 5,651,158 issued Jul. 29, 1997 to Hans Halm discloses a toothbrush handle with a segmented head wherein adjoining segments are linked by an elastomeric material. The segments are primarily oriented transverse to the longitudinal axis of the toothbrush but may also be oriented parallel to that axis.
U.S. Pat. No. 6,408,476 discloses another form of segmented toothbrush head with transverse grooves and an elastomeric portion joining the segments. A method of manufacturing this head is also disclosed.
The use of elastomeric material within folds of a toothbrush handle is the subject of U.S. Pat. No. 5,903,949.
International Publication Number WO96/02165 dated Feb. 1, 1996 discloses a resiliently flexible bristle-bearing toothbrush head containing bristles with a generally concave surface. The head, being flexible, can flex under the action of tooth brushing to accommodate the varying profiles of users' teeth. Grooves transverse or parallel to the longitudinal axis of the toothbrush which are filled with elastomeric material permit flexure along the length or across the breath of the head (pages 4-5).
A tip region of a toothbrush head is flexibly mounted to the rigid balance of the head in the disclosure of International Publication Number WO 97/07707 dated Mar. 6, 1997. A flexible plastic material forms the link (hinge) which connects the two parts of the head (pages 2-3). In use, the tip region of the head can fold backwards toward the rigid balance of the head, thereby enabling the head to better accommodate itself to the curved shape of the user's teeth.
Another flexible toothbrush head is disclosed n European Patent Specification No. EP 0577 656 B1 published May 4, 1997.